No channel and wrong location, they always go at the front of the shelf to light the contents of the shelf, you are lighting the back wall. Have them corrected. I think moved forward the shelf nosing is deep enough to hide them.

They’re actually in the center of the shelf not the back so it does light the shelf.

Move them to the front and they won’t show. In the middle they will show no matter how deep the channel is.

There’s already a channel there so isn’t it a little late to move it to the front?

How long will they bother you? Far easier to address it now even if you have to pay. I would have the cabinet maker make a 1/4” skin for the bottom of each shelf to cover the channel and essentially create a new channel at the front.